So are you still using avast4.x and if so what home/Pro and what version, e.g. 4.8.1368, etc. ?
It is highly unlikely anyone in these forums will be able to confirm that if as you say it is in the avast4 folder as avast 5 has been out for over 5 months now. I had avast 4.x for almost 6 years before installing avast5 and this file name isn't one that I'm familiar with, certainly not in the avast4 folder.
So my advice would be to do a clean install the latest version of avast5:
- Download the latest version of avast, 5.0.594 http://files.avast.com/iavs5x/setup_av_free.exe
and save it to your HDD, somewhere you can find it again (if you didn't save your last download). Use that when you reinstall.
- Download the avast! Uninstall Utility, aswClear5.exe find it here
and save it to your HDD (it has uninstall tools for both 4.8 and 5.0).
- 1. Now uninstall (using add remove programs, if you can't do that start from the next step), reboot.
- 2. run the avast! Uninstall Utility from safe mode, first for 4.8 if previously installed and then for 5.0, once complete reboot into normal mode.
- 3. install the latest version, reboot.